This flightless avian lacks feathers or even true skin, its body wrapped in several hundred layers of fine, gelatinous webbing from which it secretes thick, rubbery and incredibly sticky mucus. Foul-smelling bacteria regularly attract insects or even small vertebrates to its glue-like surface, which it feasts upon as it continuously preens itself. Ocassionally, it may fling strands of slime to lasso a far larger source of meat, and use its entire mass to suffocate the victim.

Phlegmbrain appear fascinated by winged creatures, and are most content at high elevations. They are capable of imitating absolutely any sound, and enjoy playing pranks on other beings with their mimicry.